Cinematograph film



June 19, 1928. 1,674,528

' A. H. SMITH CINEMATOGRAPH FIALM Filed June 18. 1926 I 4 2 4 nnorrnbuuuonnnn nnouq003E Z w LUDDOOUUQUODUOUDUOQUDD000 Patented June 19, 1928.

UNITED STATES 1,674,528 PATENT OFFICE.

ALBERT HENRY SMITH, F BIRMINGHAM, ENGLAND.

CINEMATOGRAI H FILM.

Application filed June 18, 1926, Serial No. 116,923, and in Great Britain June 3, 1926.

This invention comprises certain improvements in or relating to cinematograph or like films. These films have ordinarily rectangular perforations at intervals along each edge, for meshing with the teeth of feed rollers in the projecting apparatus or the like. The feed rollers are driven intermittently at considerable speed, and consequently .tlie teeth not only press against the edges of the perforations, but also have a snatching' action thereon, with the resultthat the material at the edges of the perforations cracks and tears away. This invention has for its object to obviate this defect and to considerably increase the life of the film.

According to the present improvements,

a cinematograph or like film is strengthened on one side on the full length of each edge by a flat strip or ribbon of metal which is fixed on or interlocked with the previously perforated film. The strips have tongues cut therefrom which are of a size corresponding to the size of the required perforation in the strip and which are bent through the perforations in the film and folded some around the front edges and some around the rear edges of such perforations, the strip of metal being of such a. character and so connected to the film that the film can be wound into is a close coil and bent into varying curvatures whilst passing through projecting apparatus or the like. The metal strips are also so connected to the film that creep is prevented. The said tongues of metal ale preferably pressed back on the film whilst the film and metal strips are passed around a cylindrical surface. The metal strips may also be of thinner gauge than the film, and such metal strips are preferably located on the outer side of the film.

Referring to the drawings Figure 1 is an outer face view of a por tion of a film constructed according to this invention;

Figure 2 is an inner face view.

Figure 3 is an enlarged cross sectional view, the section being taken on line a: a: of Figure 2.

Figure 4 is a longitudinal sectional elevation drawn to an enlarged scale, the section being taken on line y y of Figure 2.

Figure 5 is a. View showing the position of the film when the tongues are pressed back on the inner side of the film,

According to a convenient embodiment of this invention, the full length of the film 1 is strengthened on each edge by the metal strips or ribbons 2, located on the outer face of the film. These metal strips have tongues 3 pierced therefrom and such tongues are straight path. As the metal strip is positioned on the outer face of the film the length of metal strip passing round a curved portion of the film will vary slightly from the length of metal strip lying on a correspondingly straight portion of the film, and therefore a slight movement between the film and metal strip is provided for, whilst at the same time the metal strips are prevented from creeping bodily in relation to the film. The metal tongues 3 for this purpose are preferably pressed around the edges of the perforations in such a manner that a small space 5 is left between the edge of the perforation and the inside of the tongue. To preventthe strips creeping bodily some tongues are bent forwardly and some tongues 2 are bent rearwardly. When the film is passing through the gate of the projecting machine the edges of the tongues 3 are rearwardly directed, whilst the edges of the tongue 2 are forwardly directed. The tongues 2 are therefore more liable to be lifted, but this liability is prevented by the protection afforded by the tongues 3 which protect the edges of the tongues 2. The tongues are pressed back on the film whilst the film and metal strips are bent round a cylindrical surface 'as shown by Figure 5. In order to give sufficient flexibility to the metal strips so that the fihn is not damaged in use such metal strip is of a thinner gauge than the fihn and for ordinary films at present in use the metal strips are .conveniently three thousandths of an inch thick and formed of phosphor or other bronze or other metal which can berolledor formed into thin strips, and possesses the required flexibility and strength. The flexibillty of such strips between the points of attachment also allows a slight movement to take place between the strips and the film to enable the strengthened film to take up any curvature in use. The physical properties of the phosphor or like bronze strips are such that the tongues can be bent to lie close against the film and are not liable to be liftedduring the coilingand recoiling in the V v i film has heretofore usually been governed by the damage received at the edges of the perforations. The metal ribbon also protects the face of the film from scratches, whilst moreover the liability of the film being broken is reduced to a minimum. The edges of the film will be prevented from fraying and liability of the film catching fire is considerably minimized. '7 V Iclaim': i In a device'of the class described, a film having driving-wheel perforations arranged in a longitudinal line adjacent to one edge of the film, and a reenforcing strip on one 7 surface of the filmand extended longitudinally' of the film, the strip being provided with perforations registering with the perforations of the film, the material freed in the formation of the perforations of the strip being fashioned into tongues whichare extended through the perforations of the film and overlapped on the opposite surface of the film,' spaced pairs of adjoining tongues being extended toward each other in opposite directions, and all of the tongues intervening between the said pairs project. ing in one'direction, the edge of the perforation in the strip that is opposite to'each of said intervening tongues being plain.

In witness whereof I have signed this specification.

' ALBERT HENRY SMITH. 

